目的:探讨后路寰枢椎椎弓根螺钉内固定的术前计划方案,明确其手术指导意义。方法:选取经CT评估寰枢椎椎弓根螺钉置入可行的,并拟选择该手术治疗的上颈椎不稳患者15例,容积再现重建(VR)寰枢椎椎弓表面影像,了解个体椎弓后方表面解剖形态与骨性解剖标志。同时按寰枢椎椎弓根理想的钉道走行,多平面重建(MPR)个体椎弓根断面影像。术前根据这些解剖影像设计手术暴露路经、理想的进钉点与钉道轨迹。术中按该术前计划手术暴露,找到理想的进钉点并钻孔置椎弓根螺钉。将术中观察到的C1后弓及C2椎弓表面解剖,与术前CT重建影像对比。术后CT复查,评价螺钉置入情况。结果:15例术中观察到的C1后弓及C2椎弓表面解剖特征与术前CT容积再现的影像一致。参照寰枢椎椎弓CT影像解剖制定术前计划方案,术中按其逐一操作,手术简单、直观,无重要血管神经损伤,置钉准确。结论:根据CT容积再现与多平面重建的寰枢椎解剖影像,制定后路寰枢椎椎弓根螺钉内固定术前计划方案,指导手术安全、可靠。
ObjectiveTo evaluate the stability of the fixation technique for the crossed rods consisting of occipital plate and C2 bilateral lamina screws by biomechanical test.MethodsSix fresh cervical specimens were harvested and established an atlantoaxial instability model. The models were fixed with parallel rods and crossed rods after occipital plate and C2 bilateral laminae screws were implanted. The specimens were tested in the following sequence: atlantoaxial instability model (unstable model group), under parallel rods fixation (parallel fixation group), and under crossed rods fixation (cross fixation group). The range of motion (ROM) of the C0-2 segments were measured in flexion-extension, left/right lateral bending, and left/right axial rotation. After the test, X-ray film was taken to observe the internal fixator position.ResultsThe biomechanical test results showed that the ROMs in flexion-extension, left/right lateral bending, and left/right axial rotation were significantly lower in the cross fixation group and the parallel fixation group than in the unstable model group (P<0.05). There was no significant difference between the cross fixation group and the parallel fixation group in flexion-extension and left/right lateral bending (P>0.05). In the left/right axial rotation, the ROMs of the cross fixation group were significantly lower than those of the parallel fixation group (P<0.05). After the test, the X-ray film showed the good internal fixator position.ConclusionThe axial rotational stability of occipitocervical fusion can be further improved by crossed rods fixation when the occipital plate and C2 bilateral lamina screws are used.
ObjectiveTo investigate the accuracy of progressive three-dimensional navigation template system (abbreviated as progressive template) to assist atlas-axial pedicle screw placement. MethodsThe clinical data of 33 patients with atlas-axial posterior internal fixation surgery between May 2015 and May 2017 were retrospectively analyzed. According to the different methods of auxiliary screw placement, the patients were divided into trial group (19 cases, screw placement assisted by progressive template) and control group (14 cases, screw placement assisted by single navigation template system, abbreviated as initial navigation template). There was no significant difference in gender, age, cause of injury, damage segments, damage types, and preoperative Frankel classification between the two groups (P>0.05). The operation time and intraoperative blood loss of the two groups were compared. The safety of screw placement was evaluated on postoperative CT by using the method from Kawaguchi et al, the deviation of screw insertion point were calculated, the angular deviation of the nailing on coordinate systems XOZ, XOY, YOZ were calculated according to Peng’s method. ResultsAll patients completed the operation successfully; the operation time and intraoperative blood loss in the trial group were significantly less than those in the control group (t=–2.360, P=0.022; t=–3.006, P=0.004). All patients were followed up 12–40 months (mean, 25.3 months). There was no significant vascular injury or nerve injury aggravation. Postoperative immediate X-ray film and CT showed the dislocation was corrected. Postoperative immediate CT showed that all 76 screws were of grade 0 in the trial group, and the safety of screw placement was 100%; 51 screws were of grade 0, 3 of gradeⅠ, and 2 of gradeⅡ in the control group, and the safety of screw placement was 91.1%; there was significant difference in safety of screw placement between the two groups (χ2=7.050, P=0.030). The screw insertion point deviation and angular deviation of the nailing on XOY and YOZ planes in the trial group were significantly less than those in the control group (P<0.05). There was no significant difference in angular deviation of the nailing on XOZ between the two groups (t=1.060, P=0.290). ConclusionCompared with the initial navigation template, the progressive navigation template assisting atlas-axial pedicle screw placement to treat atlas-axial fracture with dislocation, can reduce operation time and intraoperative blood loss, improve the safety of screw placement, and match the preoperative design more accurately.
Objective To explore the surgical feasibil ity and cl inical outcome of transpedicle screw fixation in treatment of atlantoaxial instabil ity and dislocation. Methods From January 2007 to June 2009, 16 patients with atlantoaxial instabil ity and dislocation were treated with transpedicle screw fixation. There were 13 males and 3 females, with a mean age of 42 years (range, 24-61 years). The transpedicle screw fixation was employed in 5 patients with old odontoid fracture (4 of Anderson type II and 1 of type III), in 4 patients with fresh odontoid fracture, in 4 patients with traumatic disruption of transverse atlantal l igament, and in 3 patients with congenital odontoid disconnection for atlantoaxial instabil ity. All patients had symptoms of cervical pain and l imition of cervical motion, 10 patients compl icated by dyscinesia and hypoesthesia of extremities. The Japanese Orthopaedic Association (JOA) score before operation was from 5 to 13, with an average of 8.5. The image examination showed atlantoaxial instabil ity or dislocation in all patients. Granulated autogenous il ium (20-30 g) was placed onto the surface of the posterior arches of both atlas and axis in some patients with old fracture of odontoid process or disruption of transverse atlantal l igament. Results The mean operative time and bleeding amount were 1.6 hours (1.2-2.5 hours) and 100 mL (50-200 mL), respectively. All the incision healed by first intension. All patients were followed up for 3-18 months, with an average of 11.5 months. The JOA score 3 months after operation was from 12 to 17, with an average of 14.2. All screws were successfully placed in atlas and axis. No postoperative compl ications such as vertebral artery injury, dural rupture, exacerbation of neurological symptoms, wound infection, and broken srews were observed in 16 cases. Postoperative radiograph and CT showed that only one screw penetrated into vertebral canal, but there was no neurological symptoms. Bony fusion was observed after 6 to 18 months of operation, and atlantoaxial rotational function in all patients restored satisfactorily, but axial rotation was partially lost. Conclusion Transpedicle screw fixation in upper cervical spine for treatment of atlantoaxial instabil ity and dislocation is safe and rel iable
To study project of simpl icity and util ity for screw-plate system by pedicle of atlanto-axis mani pulatively hand by X-ray film and CT to prove the one success rate of putting screws. Methods Formulate personal program was used in operation by image save transmission of X-ray film and CT during January 2002 and September 2006 in 31 patients. There were 18 males and 13 femals, aged from 23 to 61 years old with an average age of 43.5 years. Putting screw points bypedicle of atlas were measured: left (19.93 ± 1.32) mm, right (19.16 ± 1.30) mm; putting screw obl iquity angle to inside by pedicle of atlas: left (23.72 ± 2.09)°, right (23.35 ± 1.91)°; putting screw obl iquity angle to side of head by pedicle of atlas: (9.00 ± 1.20)°. Screw points by pedicle of axis: left (13.14 ± 0.82) mm right (13.85 ± 0.79) mm; putting screw obl iquity angle to inside by pedicle of axis: left (24.52 ± 1.26)°, right (20.42 ± 1.42)°; putting screw obl iquity angle to side of head by pedicle of axis: (25.00 ± 3.00)°. The domestic location toward speculum was employed in operation and putting screw points and angles were formulated by X-CT program. The pedicle screws of suitable diameter and length were of exception and screws into pedicle of atlanto-axis were put by hand. Results Pain of the greater occipital nerve occurred in 2 patients after operation and was fully recovered by treatment 1 month after operation. The lateral cortical bone of pedicle was cut by 2 screws, but the spinal cord and vertebral artery were fine. The atlas and the fracture of odontoid process of axis were completely replaced in X-ray films of all patients 1 day after operation.The position relation of lag screw and vertebral artery or spinal cord was very good in CT sheets. All cases were followed up with an average of 10.5 months during 9 months to 5 years and 4 months, and obtained atlantoaxial arthrodesis. The breakage of screw and plate was not found in all cases. According to JOA score standard, 16 cases were excellent, 12 were good, 2 were fair, 1 was poor, and the excellent and good rate was 90.32% . Conclusion The personal design and cl inical appl ication of X-ray films and CT sheets are of great significance to screw-plate system by pedicle of atlanto-axis because of simpl ification of designs and methods and better personal ity.
【摘要】 目的 探讨利用术前CT多平面重建（MPR）图像上钉道设计与术中确定枢椎峡部中心，指导后路寰枢经关节螺钉内固定徒手置钉的价值。 方法 选取成人头颈尸体标本9具，及寰枢关节不稳患者5例，螺旋CT扫描，取后路寰枢经关节螺钉内固定的理想钉道（经枢椎峡部中心点）所在平面重建并设计个体化钉道，确定安全的置钉范围。参考术前钉道设计与术中确定枢椎峡部中心，徒手行后路寰枢经关节螺钉固定。术后对实际钉道CT多平面重建，分析徒手实际置钉情况。 结果 后路寰枢经关节螺钉固定共28侧，术中徒手操作顺利，无重要血管神经损伤。手术实际钉道均在术前设计钉道的安全范围内。5例患者寰枢椎间术后较术前存在相对位移变化。 结论 根据螺旋CT MPR图像设计的个体化后路寰枢经关节螺钉内固定钉道，结合术中枢椎峡部中心显露，可指导临床安全地徒手置钉。【Abstract】 Objective To explore the clinical value of the free-hand technique on making the screw path of posterior atlantoaxial transarticular screw fixation, which guided in accordance with the preoperative design of the screw trajectory in spiral CT multilevel reconstruction (MPR) imaging and intra-operative exposure of the center of C2 isthmus. Methods The cervical spine segments of 9 human cadavers and 5 patients with atlantoaxial instability were scanned with spiral computed tomography. Then the CT MPR images of ideal screw trajectory of posterior atalanto-axial transarticular screw reconstructed through the central point of C2 isthmus were used for plotting individual safe screw trajectory. According to preoperative designing of the individual screw trajectory and intraoperative exposure of the center of C2 isthmus, free-hand operation made the transarticular screw path of posterior atlantoaxial screw fixation. Postoperative CT MPR image was used to analyze the actual screw trajectory in atlantoaxial complex, as well. Results The transarticular screws were inserted atlantoaxial joints in 28 sides. The free-hand operation of screw placement was successful, and no screw misplacement or major neurovascular injury was found. There was relative displacement between the atlas and axial vertebrae in 5 patients. Conclusion The free-hand technique of posterior atlantoaxial transarticular screw placement is reliable and safe which refers the preoperative individual screw trajectory designed by CT MPR image and intraoperative exposure of the center of C2 isthmus.
ObjectiveTo investigate reliability and short-term effectiveness of axis laminar screws for reducible atlantoaxial dislocation (RAAD).MethodsA clinical data of 41 patients with RAAD who were admitted between February 2013 and February 2018 and met the inclusion criteria was retrospectively analyzed. The atlases in all patients were fixated by lateral mass screws, and the axes were fixed by laminar screws in 13 cases (LS group) and by pedicle screws in 28 cases (PS group). There was no significant difference in gender, age, and preoperative Japanese Orthopedic Association (JOA) score between the two groups (P>0.05). The effectiveness was estimated by post-operative JOA score; and the accuracy of the axis screw, atlantoaxial bone graft fusion, and the fixation stability were examined by X-ray film and CT.ResultsAll incisions healed by first intention. All patients were followed up 12-17 months (mean, 13.8 months) in LS group and 12-20 months (mean 14.1 months) in PS group, and the difference in follow-up time was not significant (Z=−0.704, P=0.482). At last follow-up, JOA scores were 13.9±1.6 in LS group and 14.3±1.8 in PS group, which significantly improved when compared with the pre-operative scores in the two groups (t=−9.033, P=0.000; t=−15.835, P=0.000); while no significant difference was found between the two groups (t=−0.630, P=0.532). Twenty-five screws of 26 screws in LS group and 54 screws of 56 screws in PS group were implanted accurately, with no significant difference in the accuracy of the axis screw between the two groups (Z=−0.061, P=0.951). All patients obtained atlantoaxial bone graft fusion, except 1 case in PS group. There was no significant difference in the atlantoaxial bone graft fusion between the two groups (Z=−0.681, P=0.496).ConclusionFor RAAD, Axis laminar screws can maintain the atlantoaxial primary stability and had a good short-term effectiveness. So, it could be an alternative and reliable technique for axis screw.
ObjectiveTo evaluate the effectiveness of the posterior atlantoaxial lateral mass screw fixation and suboccipital decompression in the treatment of Arnold-Chiari malformation associated with atlantoaxial joint dislocation. MethodsBetween September 2012 and November 2015, 17 cases of Arnold-Chiari malformation associated with atlantoaxial dislocation were treated by the posterior atlantoaxial lateral mass screw fixation and suboccipital decompression and expansion to repair the dura mater and bone graft fusion. There were 10 males and 7 females, aged 35-65 years (mean, 51.4 years). The disease duration was 14 months to 15 years with an average of 7.4 years. According to Arnold-Chiari malformation classification, 13 cases were rated as type I, 3 cases as type II, and 1 case as type III-IV. Cervical nerve root stimulation and compression symptoms were observed in 12 cases, occipital foramen syndrome in 11 cases, cerebellar compression symptoms in 6 cases, and syringomyelia in 10 cases. ResultsPrimary healing of incision was obtained in the other patients except 1 patient who had postoperative cerebrospinal fluid leakage after removal of drainage tube at 3 days after operation, which was cured after 7 days. All patients were followed up 6 months to 2 years, with an average of 18.4 months. The neurological dysfunction was improved in different degrees after operation. The Japanese Orthopedic Association (JOA) score was significantly increased to 16.12±1.11 at 6 months from preoperative 11.76±2.01 (t=13.596, P=0.000); compression of spinal cord and medulla was improved. X-ray examination showed bone graft fusion at 6 months after operation. In 10 patients with spinal cord cavity, MRI showed empty disappearance in 3 cases, empty cavity lessening in 6 cases, and no obvious change in 1 case at 6 months. ConclusionAtlantoaxial lateral mass screw fixation and suboccipital decompression and expansion to repair the dura mater can obtain good effectiveness in the treatment of Arnold Chiari malformation associated with atlantoaxial transarticular dislocation.
Objective To explore the feasibility and effectiveness of spinal pedicle screw internal fixation through endoscope-assisted posterior approach for the treatment of traumatic atlantoaxial instability. Methods Between September 2008 and September 2010, 44 patients with traumatic atlantoaxial instability received spinal pedicle screw internal fixation through endoscope-assisted posterior operation (micro-invasive surgical therapy group, n=22) or traditional surgical therapy (control group, n=22). There was no significant difference in gender, age, type of injury, disease duration, and preoperative Japanese Orthopedic Association (JOA) score between 2 groups (P gt; 0.05). The blood loss, operation time, length of the incision, improvement rate of JOA, and graft fusion rates were compared between 2 groups to assess the clinical outcomes. Results The blood loss, operation time, and length of the incision in the micro-invasive surgical therapy group were better than those in control group (P lt; 0.05). All incisions were primary healing. Of 88 pedicle screws, 7 pedicle screws penetrated into the interior walls of cervical transverse foramen in the micro-invasive surgical therapy group and 8 in the control group, but there was no syndrome of vertebral artery injury. All patients of the 2 groups were followed up 12 to 37 months (mean, 26 months). Bony fusion was achieved in all cases within 3 to 12 months (mean, 5.3 months). No loosening or breakage of screw occurred. At 6 months to 1 year after operation, the internal fixator was removed in 6 cases and the function of head and neck rotary movement were almost renewed. The JOA score was significantly improved at last follow-up when compared with preoperative score (P lt; 0.05), and no significant difference in JOA score and improvement rate between the 2 groups at last follow-up (P gt; 0.05). Conclusion The micro-invasive surgical therapy can acquire the same effectiveness to the traditional surgical therapy in immediate recovery of stability, high graft fusion rate, and less complication. Moreover, it can significantly reduce the operation time, blood loss, and soft tissue injury, so this approach may be an ideal way of internal fixation to treat traumatic atlantoaxial instability.